﻿// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

using System.CodeDom;

namespace System.ComponentModel.Design.Serialization;

/// <summary>
///  Implement this interface on a CodeDomProvider to optimize reloading in the designer. When the designer
///  goes to reparse a file, it will reparse the top level of the file, and then pass the new CodeCompileUnit to
///  the ShouldReloadDesigner method, which returns true if the designer should be reloaded. Reloading generally occurs
///  when the code inside the methods that the designer has generated, such as InitializeComponent have changed.
///  Otherwise, it is unnecessary to take the performance hit of reloading the designer.
/// </summary>
public interface ICodeDomDesignerReload
{
    /// <summary>
    ///  If ICodeDomDesignerReload is implemented on a CodeDomProvider that is in use by the designer,
    ///  ShouldReloadDesigner will be called before a reload occurs.
    ///  Reloads generally occur when a user switches from design view to code view, modifies the code, and switches
    ///  back to design view. ShouldReloadDesigner allows the CodeDomProvider implementation
    ///  to decide if code that is relevant to the designer has been modified
    ///  -- usually this is the code that the designer generated when the user saved or went to code view.
    /// </summary>
    bool ShouldReloadDesigner(CodeCompileUnit newTree);
}
